By Dr. Becker
The U.S. is home to 74 million to 96 million pet cats, living in about 37 percent of households.1 For cat lovers, their presence in your home probably feels like second nature, and you may not be able to imagine life without your precious feline companion.
But it wasn't always this way. At some point, cats weren't pets but wild animals. While the origin of pet dogs is relatively established (it's thought that all dog breeds share a common ancestor, the gray wolf), how cats came to be domesticated is far more of a mystery.
There's even debate over whether house cats are actually domesticated, meaning their behavior and anatomy are distinct from that of wild cats.
Research presented at the 7th International Symposium on Biomolecular Archaeology in Oxford, U.K. in September 2016 provides some intriguing insight into this now age-old question.
Ancient Cats May Have Hitched Rides With Farmers and on Viking Ships
Researchers from the Institut Jacques Monod in Paris, France sequenced DNA from more than 200 cats living in ancient times (some 15,000 years ago, before the advent of agriculture when humans lived as hunters and gatherers) up until the 18th century.
It's the largest genetic analysis of ancient cats to date, and it's revealed some clues about ancient cats' origins and how they eventually spread throughout the world.
Mitochondrial DNA (which is inherited from the mother only) from cats found at more than 30 archaeological sites in Europe, the Middle East and Africa — including ancient Egyptian tombs, Cyprus burial grounds and a German Viking settlement — was analyzed, revealing that cats spread in two primary waves.
Cats in the Middle East and eastern Mediterranean shared a mitochondrial lineage. The researchers suggested wild cats may have been drawn to early farming communities in the eastern Mediterranean, where grain stockpiles attracted plenty of rodents.
The farmers likely appreciated the cats' rodent-catching skills and may have started to tame them.
A shared mitochondrial lineage was also found among Egyptian cat mummies and cats in Bulgaria, Turkey and sub-Saharan Africa from the end of the 4th century B.C. to the 4th century A.D. This same DNA lineage was also found at an 8th to 11th century Viking settlement in northern Germany.
It's likely that Vikings and other sailors invited cats onto their ships to help control rodents, furthering the domestication of felines.2
Funding for Cat Domestication Research Is Scarce
Part of the reason why cats' origins remain a mystery has to do with a lack of financial resources. Funding for such cat domestication research falls far short of its canine counterpart.
A study to sequence nuclear DNA, which reveals important information about an individual's ancestors, could help to shed more light on cat domestication, including their ties with wild cats.
Such a study is underway in dogs, with plans to sequence nuclear DNA from more than 1,000 ancient dogs and wolves, Nature reported, but funding is lacking to do so in cats.
"We can do it, too," study author Eva-Maria Geigl, Ph.D., told Nature, referring to sequencing nuclear DNA from ancient cats. "We just need money."3
Cats May Be Only Semi-Domesticated
Learning the origins of cat domestication is all the more intriguing in light of another unknown: Are cats fully tame? There are signs that suggest the answer is no, and cats may, in fact, be a semi-domesticated pet.
One study published in the Proceedings of the National Academy of Sciences (PNAS) revealed certain genes in cats affecting memory, fear-conditioning behavior and stimulus-reward learning that they believe are involved in domestication.4
Despite this, the authors still suggested cats are only semi-domesticated. Arguments in support of the semi-domesticated camp point out that cats are often independent and "pretty much take care of themselves," Wes Warren, Ph.D., a biologist at Washington University in St. Louis and senior author of the PNAS study, told Slate.5
They don't need to be housebroken the way dogs do and retain the ability to hunt virtually as well as wild cats. Warren continued, "When you look at the molecular signatures of domestication, there are 10 times more in dogs than in cats."6
Others disagree, however, noting that many cats are as affectionate as dogs, if not more so, and actively seek out human attention.
David Grimm, Ph.D., author of "Citizen Canine: Our Evolving Relationship With Cats and Dogs," had this to say in response to the question of whether cats are wild or domestic. I'm sure you have your own opinion as well.
"They can be aloof and mysterious, and when they go outside they blend into the savage world around them, stalking, growling and leaping — their eyes wide, their ears back [and] their teeth bared. They are the kings of their backyard jungles.
Yet they give it all up to be with us — a loud, erratic and sometimes incomprehensible species. When they cross our thresholds, the beast fades away. They tame us, and they are tamed by us. Cats may have retained a bit of their wild ancestry, but they always come home." 7